Please help me solve this question already tried two times don't seem to know how to get it!

Assume that Flounder Company uses a periodic inventory system and has these account balances: Purchases $476,000; Purchase Returns and Allowances $12,200; Purchase Discounts $7,800; and Freight-In $19,700. Flounder Company has beginning inventory of $66,900, ending inventory of $90,700, and net sales of $748,600. Determine the amounts to be reported for cost of goods sold and gross profit. Cost of goods sold $ Gross profit $